Artisyn Synthetic Paper – 10 Mil is a great alternative to NG Adventure paper, and is sold by the single sheet. Only avail. in letter size. Shipping is $6.
At 67 cents a sheet ($0.69 for less than 50 sheets) it is a good deal:
http://www.arcadiaid.com/product_info.php?cPath=24&products_id=3
